A High-definition Digital Media Interface (HDMI) cable and an optical fiber cable are widely used as bidirectional communication interface devices.
For connection using HDMI, HDMI Audio Return Channel version 1.4 (HDMI-ARC) improved in transfer of audio signals, and HDMI Ethernet Channel (HDC) version 1.4 capable of exchanging control signals over Ethernet (registered trademark) have been established.
In accordance with demands for a faster transfer speed or for a longer transfer distance, a cable capable of high-speed communication like 10-Gigabit Ethernet (10 GbE) conforming to the Institute of Electrical and Electronics Engineers (IEEE) 802.3ae standard has already been put into practice for unidirectional communication only.
Further, there has been disclosed a method for introducing bidirectional Ethernet communication into an HDMI system by forming a single communication channel.
Aiming for high-speed long-distance transfer, an HDMI cable has been proposed which includes a waveform equalizer using an active element and has signal lines each being single-directional. A cable as described is adequate for an optical transfer cable. When each of signal transfer directions in a cable is limited to a single direction, a conventional system has difficulties in maintaining compatibility with devices of early models.
An embodiment is directed to providing a signal transfer system which is capable of using a multi-core cable including signal lines each having a single transfer direction and is also capable of improving compatibility with conventional devices.